Mouthpiece for telephones



July 2, 1929. v. J. TRACY v 1.719.573

MOUTHPIECE FOR TELEPHONES Filed Aug. 31, 1927 Patented July 2, 1929.

VERNON J. TRACY, or LOS ANGELES, CALIFORNIA.

MOUTHPIECE iron 'rnnnrnonns.

A'pp lieation filed Au usta, 1927: Serial no. 216,597.

This invention relates to telephones and;

particularly to telephone transmitters. Frequently, in holding aconversation over the telephone, it may be desired by the. persontelephoning to talk with persons in his presence without having thetelephone transmit his conversation.

The general object of this invention is to provide simple means forenabling the function of the transmitter to be temporarily inhibited soas to prevent it from transmitting a private conversation and atthc sametime to construct the device in such a way as not to interfere with theordinary use of the instrur ment.

Further objects of the invention will appear hereinafter.

The invention consists of the novel parts and combination, of parts tobe described here inafter, all. of which contribute to produce anefficient mouthpiece for telephones.

A preferred embodiment of the invention is described in the followingspecification, while the broad scope of the invention is pointed. out inthe appended claims.

In the drawing:

Figure 1 is a side elevation of a transmitter and showing the mouthpiecewith my improvement in cross-section.

Figure 2 is a front elevation of the transmitter with my improvement.

Figure 3 is a cross-section through a device ilhistrating anotherembodiment of my invention and showing a portion of the outer end of themouthpiece of a telephone transmitter.

Figure t is a front elevation of the embodiment of the invention shownin Figure 5.

In practicing the invention I provide means associated with themouthpiece in such a way that by a slight movement of ones hand theopening through the mouthpiece can be closed, thereby preventing thetransmission of any sound through the telephone. This may beaccomplished in various ways. I prefer to employ means for engaging theedge of the mouthpiece to secure the device in position. The deviceincludes a plug located within the mouthpiece and movable inward- 1y soas to close the orifice through the mouthpiece. Between this plug andthe edge of the mouthpiece I provide yielding means for normally holdingthe plug in its withdrawn position so as to leave the orifice clear andunobstructed.

In the preferred embodiment of the invention disclosed in Figure'1 Iconstruct the device. as an attachment "for the mouthpiece 1 of thetelephone transmitter 2. This attachment-consists of a disc 3 of rubberor similar materialwhich isprovided with a flange 1 at its edge toenableit to be slightly stretched and applied over the outer end of themouthpiece. I

The body of this disc is provided. with perforations 5 which enable thesound to pass through the disc to the interior of the mouthpiece. At itsmiddle point the disc is pro-. vided with a plug 6 which may be moldedintegrally with the body of-the disc. This plug is of substantiallyconical form and with its large end disposed near the perforated.diaphragm 7, at the inner end of the mouthpiece. The plug is formed atits outer end with a button 8 which projects outwardly on the forwardface of the disc. Thisbutton, however, is not essential. With this construction it will be evident that if the button 8 is pressed inwardlythe inner end of the plug 6 can be brought into engagement with thediaphragm 7 so as to close the perforations through it. The inner end ofthe plug is preferably formed with a deep conical recess 9 so that arelatively acute edge 10 is formed around the inner end of the plug.This facilitates an expansion of the plug which takes place when theplug is shoved against the diaphragm 7.

It will be noted that in an embodiment of the invention shown in Figure1,'the disc 3 itself operates as the resilient means between the edge ofthe mouthpiece and the plug for normally holding the plug in itsWithdrawn position.

In the embodiment of the invention shown in Figure 3 the body of theattachment is formed of a disc 11 of light sheet metal, which may bestamped out in quantities with a die. This disc is slightly resilientand is formed at its edge with a plurality of integral ears 12 which canbe sprung outwardly to enable the disc to be applied over the end of atransmitter mouthpiece 13, as shown in Figure 5. In this form of theinvention I provide a plug 14 which is supported on the inner end of astem 15 which is mounted to slide inwardly through an opening 16 in thecenter of the disc. Suitable means is provided .on the disc for holdingthe stem 15 in its extreme outward position. This means is preferably inthe form of a spiral spring 17, one end of which is secured to a hook 18formed on the inner side of the disc, the other end of the spring beingsecured by a pin 19 to the stem 15. If desired, the stem may be threadedinto the outer end of the plug. The function of the spring is, ofcourse, to hold the stem and plug in the position in which they areillustrated in Figure 5, and to return them to this position after theplug has been forced inwardly.

It is understood that the embodiment of the invention described hereinis only one of the 'many embodiments this invention may take, and I donot Wish to be limited in the practice of the invention, nor in theclaims, to the particular embodiment set forth.

WVhat I claim is:

1. An attachment for the mouthpiece of a telephone consisting of a dischaving means at its edge for securing the same to the outer end of themouthpiece and having a central plug yieldingly held in place, locatedon the inner face of the disc and movable longitudinally by pressing onthe central axis of the disc to close the opening through themouthpiece.

2. An attachment for the mouthpiece of a telephone consisting of a dischaving means at its edge for attaching it to the outer end of themouthpiece, and a central plug disposed on the central axis of the disc,said disc being of resilient material so as to enable the plug to bemoved inwardly'on its axis to close the opening through'the mouthpiece.

3. An attachment for the mouthpiece of a telephone consisting of amember having means at its edge for engaging the edge of the mouthpiece,and a plug supported by the said member and movable longitudinallyinwardly Within the mouthpiece to close the

